It is well known in the photographic art that various polymers are used as mordants to prevent dye transfer. Such polymer mordants are disclosed in U.S. Pat. Nos. 3,898,088, 3,958,995, 4,131,469, and 4,147,548, West German patent application (OLS) No. 2,941,818, and Japanese patent application (OPI) Nos. 30328/78 and 17352/81 (the term "OPI" as used herein means an "unexamined published application").
Polymer mordants which suffer less from chemical change or decomposition of the dye image due to light are disclosed in British Pat. Nos. 2,011,912 and 2,093,041, and U.S. Pat. No. 4,282,305. However, these polymer mordants are disadvantageous in that due to their poor mordancy a prolonged period of time is required for dye transfer. This is a fatal defect in instant color photography applications.
These polymer mordants are also disadvantageous in that due to their poor mordancy dyes are released and then diffuse into the photographic material, deteriorating image sharpness.
On the other hand, U.S. Pat. Nos. 3,958,995 and 4,193,800 disclose water-insolubilized polymer latex mordants. Such polymer latex mordants are excellent at retaining dyes and are extremely less apt to diffuse into the material. However, it has been found that when a photographic print containing a dye mordanted by such a mordant is irradiated with light from a fluorescent lamp or mercury lamp or sunlight, the dye suffers from a chemical change or decomposition. When such chemical change or decomposition causes a decrease in the density of dye image, the picture quality of the photographic print becomes remarkably poor.